This invention relates to a vertical engine for a walk behind type of lawn mower and more particularly to an improved cooling arrangement for such an engine and also to a component layout for the engine that facilitates manipulation of the mower.
The rotary type lawn mower is a very popular type of mower. With such mowers, there is provided a cutting blade that is contained within the mower outer housing and which rotates about a generally vertically extending axis. The cut grass is discharged through a discharge chute formed in the mower housing. The rotary blade is driven by an internal combustion engine that is supported upon the mower housing and which has its output shaft also rotating about a vertically extending axis and coupled to the cutter blade for driving the cutter blade.
With this type of mower, it is the normal practice to provide an air cooling system for the engine. Although this type of mower has considerable advantages, there are certain difficulties in designing a mower that will be completely satisfactory. For example, in order to provide effective air cooling for the engine, the engine is normally provided with some form of cooling shroud and a cooling fan is driven by the engine output shaft for circulating air through the cooling shroud and across the components of the engine to be cooled. However, the air flow through the cooling shroud can easily become obstructed if grass clippings, which tend to swirl around the mower housing, are drawn into the cooling shroud. The accumulation of grass clippings within the cooling shroud will, obviously, adversely effect the cooling efficiency and can give rise to difficulties.
It is, therefore, a principal object of this invention to provide an improved and simplified cooling shroud arrangement for a rotary type lawn mower.
It is another object of this invention to provide an improved cooling shroud arrangement for a mower of this type wherein the ingestion of grass clippings into the cooling shroud is avoided.
It is yet another object of this invention to provide an improved and simplified cooling arrangement for a rotary mower wherein the inlet for the cooling shroud is positioned so that grass clippings are not likely to enter it.
Rotary mowers of the type described also are supported upon four ground engaging wheels that are positioned at the opposite corners of the mower housing. Such an arrangement provides good stability and ensures an even and uniform cut height. The wheels normally are non-dirigibly connected to the mower housing and hence in order to steer the mower it is necessary to lift the front wheels from the ground. However, the component layout for mowers of this type often times does not provide a rearwardly positioned center of gravity that would facilitate such movement.
It is, therefore, a further object of this invention to provide a component layout for a rotary type lawn mower wherein turning is facilitated.
It is a further object of this invention to provide a component layout for a rotary type of lawn mower wherein the center of gravity is rearwardly disposed so as to facilitate lifting of the front wheels from the ground for steering purposes.